As conventional methods of extracting a scene change from a moving image, a method of computing changes in histogram of colors of frames that form the moving image, and detecting an evaluation value by executing some threshold value process, a method using motion vector information which is used in MPEG2 or the like, and the like have been proposed.
The method using the histograms has merits such as low computation cost, high-speed processing, and high real-time performance, but has the following demerits. That is, a scene change cannot be detected from scenes having similar histograms, or scene changes are excessively detected due to an abrupt deformation or rotation of an object.
On the other hand, the method using a motion vector can assure high precision, and can also be used in other applications such as object extraction and the like, but requires much time for computations, resulting in poor real-time performance. Even when motion vector information is extracted from data encoded by MPEG2 and motion vector computations are omitted, since the precision of these motion vector computations depends on the performance of an encoder, high performance cannot always be guaranteed for all MPEG2 files.